Nosema (microsporidian)

Nosema is a genus of microsporidian parasites. The genus, circumscribed by Swiss botanist Karl Wilhelm von Nägeli in 1857, contains 81 species.[1] Most parasitise insects and other arthropods, and the best-known Nosema species parasitise honeybees, where it is considered a significant disease by beekeepers, often causing a colony to fail to thrive in the Spring as they come out of their overwintering period.

Nosema locustae, which parasitises locusts and grasshoppers; and Nosema grylli, which parasitises crickets, have been transferred to Paranosema, or in the former case Antonospora. Nosema algerae, which parasitises anopheline mosquitoes has been transferred to Brachiola. Nosema kingii, which parasitises fruit flies, and Nosema acridophagus, which parasitises grasshoppers, have been transferred to Tubilinosema.

Studies of DNA sequences imply that the boundaries between the genera Nosema and Vairimorpha are incorrectly drawn.